Split stitch vs Split back stitch.
I performed a small experiment to see the difference between Split Stitch/ Medieval Split Stitch and Modern Split back stitch. In these pictures you can see that the split back stitch uses almost three times the silk that the split stitch uses. I used Splendor 12 ply and filament silk to see the differences. From the front it all looks the same. But, from the back you can clearly see the difference in the amount of thread used.